As is well known in the prior art, a skateboard typically includes an elongated deck having an upper surface and a lower surface. The upper surface supports the feet of the skateboard rider and the lower surface has two sets of trucks that are longitudinally spaced. Skateboard trucks have attached front and back sets of wheels that have the ability to both travel over an up and down range as well as pivot around a central point forward and aft. A central axle extends through the trucks and into the wheels which are rotatably attached to the ends of the trucks.
The rider stands on the upper surface of the board and by shifting the location of the feet and center of gravity, tilts the board to cause change of direction. Conventional skateboards require that a rider provide the propelling force to move, in the form of placing one of the rider's feet on the ground and pushing with that foot as the other foot remains on the top surface of the board. By virtue of the manual propulsion, a conventional skateboard has limitations in both speed as well as the fact that the rider can tire over a period of time. To alleviate the tiring problem motorized skateboards can be utilized.
The problem with motorized skateboards is that they apply their power of acceleration, deceleration and braking to the ground via the skateboard's wheels, thus the rider is standing on the skateboard that is bearing the riders entire weight and center of gravity directly over the skateboard and its wheels. Since this condition exists, applying acceleration, deceleration or braking power to the ground via the skateboard wheels that are in direct proximity to the rider's feet causes instability to the rider and their center of gravity. When forward momentum power is applied to a motorized skateboard the sensation and condition that is created is one in which the rider feels that the board is being pushed out from under the rider. The reason for this is that power is being applied and delivered directly to the rider's feet. Only very gradual and moderate power of acceleration can be applied to avoid this condition of imbalance. Conversely, when motorized skateboards are in motion and the brakes are applied, it causes an exact opposite similar sensation and condition to the rider. On these skateboards braking causes the board to brake first, then the rider and their center of gravity second. This creates a tripping or falling forward condition and sensation. The rider must react and adjust to the stopping energy of the skateboard in order to avoid falling forward, especially under severe or hard braking conditions. Simply stated, braking on these self-contained skateboards causes the board to slow and stop before the rider's center of gravity, thereby causing an unstable condition and sensation of imbalance to the rider.
When operating the PAD the rider applies the energy of acceleration, deceleration and braking to their center of gravity, rather than applying these same energies to their feet, as is done on existing motorized skateboards. The engine or the electric d-c motor, battery, fuel tank and other elements that involved with the operation of the PAD that is of considerable weight is situated around or near the axle of the PAD drive wheel. All parts including the handle bar and controls will be balanced under, over and around, fore and aft of the axle of the drive wheel. All power of propulsion, acceleration, deceleration, and braking are applied to the ground terrestrially through the single drive wheel. All the power or energy of acceleration, deceleration and braking is applied to the rider's center of gravity from the engine/motor and the drive wheel, through the frame structure of the PAD.
A search of the prior art did not disclose literature or patents that read directly on the claims of the instant invention. However, the following U.S. patents are considered related.
PAT. NO.INVENTORISSUED5,127,488Shanahan 7 Jul. 19924,073,356Schlicht14 Feb. 19782,239,122Stokes22 Apr. 1941
The U.S. Pat. No. 5,127,488 patent discloses a power supplying accessory that can readily be retrofitted to an unpowered skateboard. The accessory includes a leaf spring having a front end and a rear end. The front end includes holes sized and spaced to fit on threaded fasteners that attach the rear truck of the skateboard. The leaf spring is secured between the rear truck and the body of the skateboard. The rear end of the leaf spring is attached to a drive assembly that includes an internal combustion engine, a drive wheel and a speed reduce. When the skateboard is loaded, the leaf spring preloads the drive wheel against the ground while the use of the rear truck of the skateboard permits the skateboard to retain its steering characteristics, thereby making it easy to learn to use.
The U.S. Pat. No. 4,073,356 patent discloses a skateboard having a fifth wheel attached to the board and coupled to a motor mounted on the board. The fifth wheel is attached to the board and extends through a slot in the board for coupling to the motor. The drive wheel does not contact the ground to drive the board unless the weight of a person on the board is distributed toward the center of the board.
The U.S. Pat. No. 2,239,122 patent discloses a power-operated vehicle that is in the form of a wheel-barrow. The vehicle allows the operator to walk with little effort while being propelled by the vehicle.
For background purposes and as indicative of the art to which the invention relates, reference may be made to the following remaining patents found in the search:
PAT. NO.INVENTORISSUED  854,299Matson21 May 19071,672,700Vass 5 Jun. 19282,257,653Russell30 Sep. 19415,020,621Martin 4 Jun. 1991